When President George W. Bush clasped hands with a supporter at a fund raising dinner, he and his Secret Service bodyguards apparently did not know that the man, according to authorities, was using a fake name and was actually wanted by the FBI for a litany of alleged crimes with a $50,000 reward for his capture.

The supporter called himself Bobby Thompson and claimed to head a generous veterans charity. But authorities said this week that fingerprints show he was actually alleged con man John D. Cody, a former military intelligence officer and Harvard Law School graduate, who was at one point wanted for questioning relating to an espionage probe.

Cody was caught this May, 25 years after first being sought, but not by the FBI and not for crimes he allegedly committed under his own name.

As an ABC News investigation detailed, a man using the name Bobby Thompson came to the attention of the U.S. Marshals for allegedly swindling over $100 million over seven years using a bogus veterans charity. As the money came in, Thompson became a political donor, giving more than $200,000 to top Republicans, which in turned allowed Thompson to get up close and personal with the powerful leaders.

Authorities said that after his scam was revealed in 2010, the man known as Thompson led law enforcement officers on a two-year-long cross-country manhunt.

He was captured by U.S. Marshals this May in Oregon, but at the time, the Marshals were unaware of Thompson's real name and, therefore, didn't know who they had. For months the suspect refused to say who he was, signing documents with the letter "X."

It wasn't until one of the Marshals, Peter Elliot, decided to take to Google and search for anything that matched the little they knew about Mr. X. After a few failed searches, Elliot said he stumbled upon an FBI list of most wanted fraud fugitives and a certain hairdo caught his eye.

"The photographs on Google images were from [John D.] Cody posing in a military uniform in 1969 with a pompadour hairstyle," Elliot told reporters Monday. "The photos looked to me like a younger version of Thompson… I believe a man is always a creature of habit, no matter what identity he takes."

Elliot learned from the FBI that Cody was wanted for allegedly stealing $100,000 and attempting to trick banks into giving him loans under false identities back in the 1980s. An FBI Most Wanted poster said Cody used as many as 13 aliases – "Bobby Thompson" wasn't included in the list – and said he was also wanted "in connection with an ongoing FBI espionage investigation."

Elliot said he showed several of his colleagues what he found and they all agreed that Cody was likely Thompson. The FBI provided fingerprints Cody had given to the military decades before and Elliot matched them with the man in custody.

"That's the kind of guy we love to catch, the kind of guy that signs his name Mr. X and challenges us," Elliot said. "It was great police work on everybody's part here. You know, thank goodness for Google. That's the bottom line."

But while the U.S. Marshals were reveling in their victory, the FBI was silent, only extending a congratulations to the Marshals for their "unrelenting determination."

According to former FBI profiler Brad Garrett, that's because the FBI should've caught Cody long ago.

"He certainly is good at being able to elude law enforcement," said Garrett, an ABC News consultant. "However, he's very blatant in some of these frauds and it would have taken not that much work, I believe, by an investigator, to have found him."

"I guess the real question is why didn't the FBI do that years ago, because it's really their case," he added.

Beyond their note of congratulations, the FBI declined to comment either about the arrest or about the unexplained espionage investigation.

As to how a fugitive with a false identity got so close to a sitting president, the Secret Service told ABC News that name checks "are just one layer of security measures put in place to ensure the safety of our protectees and venues."

"We will not comment specifically about these measures due to operational security, methods and means," Secret Service spokesperson Max Milien said.